EJ swap Alt wiring..solved! w/description of wiring

[Gloyale]

BW wire goes to the Charge light I know.

 

How about eliminateing the original external voltage regulator?

 

Any problem tapping into teh charge light wire in the engine bay at the Volt Reg. connector?

 

What have you all done?

 

Anyone with experience on an EJ swap into an early EA81?

 

Between the missing VSS, the fuel issue and this charging shiate, I am having a hard time getting this swap nailed down and running right.

 

The 84 was SOOOO much easier

Edited March 25, 2010 by Gloyale

[ShawnW]

For a VSS you may need to look into an old car that had a drive shaft mounted VSS for a cruise control unit (not a Subaru necessarily). Audiovox has an aftermarket cruise that works on most cars that might be a solution as well where you could add cruise to the car and solve the VSS issue at the same time. Roughly $100 last time I priced the kit for a Vanagon.

 

http://www.miata.net/garage/MiataCCS100.htm

[mountain brat]

i tapped mine into engine bay (chaRGE LIGHT)no probs mine is in a 86 didn't bother with vss runs fine

[GeneralDisorder]

I would pitch the VR and rewire the main junction to use the EJ's alt wireing harness.

 

I think the VR runs the stock fuel pump wiring on those old models - but you probably aren't using that anyway.

 

GD

[phantomcrooner]

I got my 2.2 into my 87 gl but it idles rough, heck it runs rough. The battery will not charge and the alt is good. I have no idea what a vehicle speed sensor does or if it even affects the running of it, but somebody told me that the engine wont run right without a VSS ans O2 sensor, is that right?

[Gloyale]

I would pitch the VR and rewire the main junction to use the EJ's alt wireing harness.

 

I think the VR runs the stock fuel pump wiring on those old models - but you probably aren't using that anyway.

 

GD

 

that's what we tried.

 

But without the VR in the circuit, it was incomplete. Tried jumpering through the connector for a few wires and could get it charging...........at 19+ volts:eek:

[GeneralDisorder]

The charge light also excites the field - so that needs to be hooked to the positive side of the battery (through the indicator lamp). Or you have to hit a critical RPM threshold for the alt to self-excite.

 

Though the alt should self-regulate..... 19v would seem to indicate a bad regulator inside the alt. It should never get that high I wouldn't think.

 

GD

[Gloyale]

The charge light also excites the field - so that needs to be hooked to the positive side of the battery (through the indicator lamp). Or you have to hit a critical RPM threshold for the alt to self-excite.

 

Though the alt should self-regulate..... 19v would seem to indicate a bad regulator inside the alt. It should never get that high I wouldn't think.

 

GD

 

Yeah it burned a fuseible link, but not before it cooked the Tachometer in the dash.

 

Could unhooking the Battery with eninge running cause the alts internal regulator to fail? The guy I did the swap for kept doing that to "test" wether the alt was charging.......I told him not to.

 

Funny thing is, if I hook a test light to the BW wire (mimicking the Charge light) It does not light.

 

I am really at a loss. I think the next step is to completely unwrap the front section of harness, and fish out all the wires associated with the regulator and eliminate them. Then, rewire directly to the voltage gauge and charge lights in the dash. We gotta pull the dash to replace it anyhow.

[GeneralDisorder]

Yeah it burned a fuseible link, but not before it cooked the Tachometer in the dash.

 

Could unhooking the Battery with eninge running cause the alts internal regulator to fail? The guy I did the swap for kept doing that to "test" wether the alt was charging.......I told him not to.

 

It's going to depend on what kind of load the battery was putting on the alt. Generally speaking, the battery is just another load like a fan, light, etc. But if the battery is low - especially if it's really low or dead - it can and will draw the FULL capacity of the alt. That is very hard on them - they are designed to run accesories and to top-off the battery - not to charge the battery.

 

Funny thing is, if I hook a test light to the BW wire (mimicking the Charge light) It does not light.

 

Yeah - you should have alternator voltage on the BW wire. That would seem to indicate a bad regulator as well and if it were hooked up properly to the dash you would see the charge indicator lamp come ON as the voltage at the battery would be higher than the voltage off the BW wire on the alt..... which is what you would expect with a burnt regulator.

 

I am really at a loss. I think the next step is to completely unwrap the front section of harness, and fish out all the wires associated with the regulator and eliminate them. Then, rewire directly to the voltage gauge and charge lights in the dash. We gotta pull the dash to replace it anyhow.

 

I would replace the alt first - charge the battery fully before installing it. Forget about the wireing on the car side - just use the EJ's wireing. Yank the EA regulator and run the EJ's large white output wire off the back of the alt straight to the fusible links. Then the BW wire through a lamp on the dash and back to positive side of the fusible links. I wouldn't even scew with the gauge cluster warning lamp - I would just mount a new one somewhere.

 

GD

[Gloyale]

 

 

I would replace the alt first - charge the battery fully before installing it. Forget about the wireing on the car side - just use the EJ's wireing. Yank the EA regulator and run the EJ's large white output wire off the back of the alt straight to the fusible links. Then the BW wire through a lamp on the dash and back to positive side of the fusible links. I wouldn't even scew with the gauge cluster warning lamp - I would just mount a new one somewhere.

 

GD

 

Yeah, we are gonna put a new Alt in it. Fully charge battery.

 

And eliminate all the VR wiring.

 

I will hook up a new temporary bulb to be a charge indicator.

 

Once I can confirm all is well, and when we get a new dash, I will rewire to the charge lamp in the dash.

[GeneralDisorder]

Sounds like a good plan. I think you have just been burned by the tendancy to think that it must be an installation problem vs. a bad part. But I think in this case the alt actually is shot - maybe it was borderline and the battery was low enough to send it over the edge.

 

GD

[Gloyale]

Alt was bad. I think it was fried by the guy running the car without the battery hooked up, or possibly when we had the External VR installed still. IDK, we tried alot of different stuff that could have toasted the alt. But anyway.........

 

It's fixed. Ended up being simpler than I imagined. Once we had a go Alt. to work with, it was easy. I didn't end up having to remove any wires. I simply unplugged the VR connector, and the original EA alt wires. Toss the VR, tape up the wires(really well)

 

Here is a description for anyone else putting an EJ into an old externally regulated EA, or really anything as the Alt operation is described here:

 

1. Heavy white wire from EJ harness direct to battery, fusible link wire at battery end for safety.

 

2. Black/white wire from alt to White/red at VR connector. This is the charge light circuit. This needs to be hooked up or the field will not excite.

 

3. Yellow wire from alt needs to be hooked to a fused power source. Prefferably a bit away from the battery. this is the "remote voltage" wire. Think of it as a monitor of the voltage "down stream" of the battery. I connected mne inside the engine bay to the White wire in the VR connector. If you had to, you could hook this wire directly to the white wire from battery at the alt........but then you're Alt. won't monitor the lower voltages further from the battery and you may not get enough charge. (battery "full", headlights dim)

 

*Note that the yellow wire continues on from there and should still be hooked to EJ harness.....goes to a diode and then through to the ECU.

[GeneralDisorder]

3. Yellow wire from alt needs to be hooked to a fused power source. Prefferably a bit away from the battery. this is the "remote voltage" wire. Think of it as a monitor of the voltage "down stream" of the battery. I connected mne inside the engine bay to the White wire in the VR connector. If you had to, you could hook this wire directly to the white wire from battery at the alt........but then you're Alt. won't monitor the lower voltages further from the battery and you may not get enough charge. (battery "full", headlights dim)

 

Interesting - on the harness I just installed the remote sense lead was simply connected right to the white lead about 6" down from the alt. That was how it was wired from the factory. This was a 90 or 91 harness - maybe different from yours? I agree that closer to the main junction would be better but apparently Subaru didn't deem it all that important for some reason.

 

Glad you got it working and the new alt fixed it up. I was pretty sure from your description that you were dealing with a bad part. That's super frustrating to have a bad part while doing a major wiring transplant since you are always second-guessing your installation.

 

GD

[Gloyale]

Interesting - on the harness I just installed the remote sense lead was simply connected right to the white lead about 6" down from the alt. That was how it was wired from the factory. This was a 90 or 91 harness - maybe different from yours? I agree that closer to the main junction would be better but apparently Subaru didn't deem it all that important for some reason.

 

 

GD

 

Harness for this swap is a 90 Legacy.

 

The EJ harness does have a heavier gauge white wire in the plug, that goes about 6 inches in and then ties to the other white wire from the battery. (that's the 3rd wire in the EJ connector....the EA's only have 2)

 

But the yellow wire, which is the remote volts wire goes up to almost the SMJ, then into a diode. It needs to have power on the alt side of the diode.

Edited March 25, 2010 by Gloyale
trying not to yell so much

[GeneralDisorder]

Yeah - you are right. I just looked at it again - forgot about the 3rd wire .

 

GD